The present invention relates generally to semiconductor processing procedures, and more particularly, to a method for cleaning a reactor chamber used in semiconductor manufacturing flow.
It is inevitable to use many types of chemicals in the semiconductor processing procedures. In such procedures, many reaction chambers are used where the chemicals are applied and reacted on the semiconductor. One major problem affecting the quality of the processed material is the unwanted deposition of chemicals on the walls of the reaction chamber ("wall deposition"). During processing, chemicals accumulate and deposit on the wall of a reaction chamber, and thus contaminate a strictly clean chemical reaction environment which is almost always required by various procedures. These deposited materials, such as silicon, oxides, nitride, copper, or aluminum, are extremely detrimental to the processing procedures since the deposited material can form particles to be dropped onto the semiconductor materials that are under active chemical reactions. It is well known that these particles are "killers" of finished semiconductor devices. Thus it is necessary to clean the reaction chamber periodically so that no significant amount of wall deposition can accumulate.
Traditionally, two major methods are used to clean the reaction chamber. A wet cleaning method requires the reaction chamber to be completely removed from its fixture and sunk into an appropriate chemical solution for several hours to strip off any build-up of the wall deposition. Although this procedure is effective in maintaining a clean reaction chamber, it is cumbersome for various reasons. For one, the reaction chamber, which may be made of a delicate material such as quartz, has to be removed and handled carefully. Moreover, the reaction chambers usually have to be cooled down from their reaction temperature, which requires an additional waiting period. Further, a large quantity of the cleaning chemicals needs to be used since the reaction chamber has to be immersed into these chemicals. Further still, once the chamber is cleaned, it has to be reassembled.
The other method to clean the reaction chamber is plasma dry etching. Plasma dry etching is advantageous because it does not require the chamber to be cooled, disassembled, removed, and immersed into a chemical solution sink. However, due to the nature of dry etching, it does not clean the reaction chamber as effectively as the wet cleaning method. The reliability of the plasma dry etching method is a significant concern.
An improved method is needed for cleaning the reaction chamber for semiconductor processing procedures. The improved method should be effective and reliable like traditional wet cleaning methods, and simple to implement like the traditional plasma dry etching methods.